i) Technical Field of the Invention
This invention relates to a keyboard instrument.
ii) Description of the Related Art
A conventional keyboard instrument 200 used in an electronic piano comprises a key 210, a hammer 220 and a chassis 230, as shown in FIG. 5. Among the above components, the chassis 230 is provided above a key bed 240, supported by two supports 250 provided on a player side and on a non-player side. An intermediate part of the chassis 230 is supported by a rib 260 extending between the two supports 250. On a top face of the chassis 230, a total of 88 keys 210 are disposed in parallel so that a free end of the respective keys 210 can swing up and down on the player side with respect to the keyboard instrument 200 and the other end can pivot on the top face of the chassis 230 on the non-player side.
The hammers 220, one each being provided per key 210, are disposed in parallel on a bottom face of the chassis 230 corresponding to an arrangement direction of the keys 210. Each hammer 220 has a free end provided with a plummet 225, and is disposed in such a way that the free end of the hammer 220 can swing up and down on the player side with respect to the keyboard instrument 200. The other end of the hammer 220 can swing about the intermediate part of the chassis 230 between the player side and the non-player side. More particularly, the chassis 230 has an insertion hole 231 provided closer to the player side than the intermediate part of the chassis 230. The hammer 220 is configured so that the free end is positioned below the chassis 230 on the player side and the other end is positioned near the top face of the chassis 230 via the insertion hole 231. The hammer 220 is further provided with a pivot shaft 226 on the other end thereof, and a tail part 221 extending further to the non-player side beyond the pivot shaft 226. The hammer 220 is attached to the chassis 230 via the pivot shaft 226. The key 210 comprises a protrusion 211 for pressing down the tail part 221 when the key is depressed. The keyboard instrument 200 further comprises a rubber switch 270 positioned between a mounting face below the top face of the chassis 230 and the tail part 221.
In the keyboard instrument 200 constituted as above, when a key 210 is depressed, the tail part 221 is depressed by the protrusion 211, and further the switch 270 is depressed by the tail part 221. As a result, a control device not shown generates a musical sound, and the free end of the hammer 220 provided with the plummet 225 swings upward. The movement of the hammer allows a player to feel as if he/she is playing an acoustic piano although he/she is playing an electronic instrument, as disclosed in Unexamined Japanese Patent Publication No. 2000-122660.
However, if the keyboard instrument 200 is rotated vertically (so that either side of the key in the key arrangement direction goes under the other side), the hammer 220 is likely to fall due to the weight of the plummet 225. Accordingly, there are cases in which one hammer 220 generates an unintended noise by hitting the adjacent hammers 220. Inhibiting such a noise is a very important task for providing a sophisticated keyboard instrument.